diff --git a/Dockerfile.delft b/Dockerfile.delft
index ab96ac3e09..0a99d18404 100644
--- a/Dockerfile.delft
+++ b/Dockerfile.delft
@@ -20,7 +20,6 @@ FROM openjdk:17-jdk-slim as builder
 USER root
 
 RUN apt-get update && \
-    apt-get -y upgrade && \
     apt-get -y --no-install-recommends install unzip
 
 WORKDIR /opt/grobid-source
@@ -87,7 +86,6 @@ ENTRYPOINT ["/tini", "-s", "--"]
 
 # install JRE, python and other dependencies
 RUN apt-get update && \
-    apt-get -y upgrade && \
     apt-get -y --no-install-recommends install apt-utils build-essential gcc libxml2 libfontconfig unzip curl \
     openjdk-17-jre-headless ca-certificates-java \
     musl gfortran \